Oil-break electric switch



May as 1926,

P.CHARPENER OIL BREAK ELECTRIC SWITCH Filed May 25, 1925 L i fie" Patented May 18,1926.

PAUL CHARPENTIER, OF PARIS, FRANCE,

STRUCTIONS ELECTRIQUES DE JEUMONT, OF PARIS, FRANCE,

. ANONYME.

PATENT OFFICE.

ASSIGNOR T0 FOBGES & ATELIERS DE CON- -OIL-BREAK ELECTRIC SWITCH.

/ Application filed May 25, 1925. Serial No. 82,762.

This invention relates to oil-break electric switches and. the like.

' The invention consists of an oil-break elec-v tric switch, cut-outor like apparatus particularly intended for producing the release of the gases produced by the rupture-arc and their escape into an expansion chamber, from the first moments of the formation of the said arc, and specially designed with a view to ensuring the energetic cooling of these gases, and to avoiding any rise of pres- Sure and therefore any explosion in the said expansion chamber.

The improved apparatus comprises in particular a cylindrical body, made of insulating material and filled with oil, communicating with a passage likewise containing oil, in which the rupture-arc is produced betweenone or more stationary contact members and one or more movable contact members of any suitable shape; this passage opens into the expansion chamber, in which the gases generated by the arc can expand without restriction.

The invention also comprises the addition of various accessory features such as an ar-. rangement for direct release at maximum load, shock resistances, and resistances for heating the oil.

Upon the annexed drawing, to which reference is made in the following description, the same letters indicate the same elements or parts.

Figure 1 represents diagrammatically the arrangement of the oil-break system.

Figure 2 is a sectional elevation of a switch constructed in conformity with the invention.

Figure 3 represents diagrammatically a modification hereafter described.

The rod or tube E, Figure 1, carries the movable contact member C and is ada ted to travel vertically under the action 0 an operating mechanism, not represented in the drawing, in a body N, preferably of cylindrical shape, having walls of insulating material and filled with oil. An opening formed in the cover N, of the body N serves asguide for the rod E.

Upon the lower edge of the body N, there is fitted a sort of funnel L, through the opening in which there passes the movable .contact member C intended to work in conjunction with the stationary contact. D, which extends almost up to this orifice, being fixed to the bottom of the expansion chamber K located beneath the body N.

The stationary contact D is surrounded by a. pipe or passage M, which flares out at its top in the form of an inverted truncated cone around the funnel L, up to a level higher than that ofthe lower edges of the said funnel, the top of the pipe being in communication with the expansion chamber K. The latter chamber is hermetically closed, butmay be provided with escape valves openin to the exterior.

When the body N of the apparatus is filled with oil, this oil passes into the pipe M through the orifice in the funnel L, until the pressure 20f the gases contained in-the chamber K balances that due to the difference of the levels ofoil in the body N and in the pipe M; this latter may communicate with a reservoir, likewise filled with oil, as will be explained hereafter.

The pressure of the gases contained in the chamber K is such that'the stationary contafctg) is only covered by a shallow depth o 01 Upon the breaking of the electric circuit controlled by the switch or cut-out apparatus, the movable contact C rises from the fixed contact D under the action of the operating mechanism, an are being produced between these contacts; the gases evolved find a passage through the shallow layer of oil covering the contact D and are able immediately to expand into the chamber K, in which there may be arranged baflles, finely divided masses or gauzes made of metal, or any other suitable device for cooling these gases.

Moreover, the saidvessel K can be filled beforehandwith inert ases, such as carbon dioxide, nitrogen and t e like.

Figure 2 shows the application of the oilbreak system, represented in Figure 1, to an oil-break switch, but it is to be understood that the system can likewise be utilized for any other oil-break apparatus, whether automatic or not, such as circuit breakers, voltage or current limiters, lightning arresters and the like.

A tube A, Figure 2,- constitutes the main movable contact, its lower end engaging'in A FRENCH socm'rE' the closed position between the fingers B on the, main stationary contact, which is of the apparatus, escapes from the fingers B;

held fast which is introduced by means device into a. longitudinal slot the tube A, the pawl H then the collar E integral with during this movement the rod E is by a pawl H of a suitable A formed in pressing upon the rod E. 4.

This slot A is of. such lengthl that after a given stroke of the tube A, the lower edge I of the slot'comes to bear upon the pawl H, which thereupon pivots around its fulcrum H and frees the rod E.

A spring G, fitted around the rod E between the block 0 and the collar E and compressed as long as the rod E is held fast by the pawl H, expands and suddenly forces the said rod E upwards as soon as the collar E is freed; the final break of the circuit then takes place between the contact members C and D.

An are being thus produced between the extremities of these contact members, the gases generated drive away the small quantity of oil covering the contact D, bend around the orifice in the funnel L, escape into the space included between the said funnel L and the bore of the passage M, and then penetrate into the expansion chamber K in which they cool off, passing for example through iron turnings or'filings before expanding. The pressure of the gases con tained in the chamber K is greater than the atmospheric pressure; it corresponds to that of a column of oil several decimetres high, depending upon the height of the insulating body N, whlch is governed by the working voltage of the apparatus; the said pressure might vary for example from one hundredth to one tenth of an atmosphere, according to circumstances.

It will be understood that the initial pressure of the gases from the arc can be only very slightly greater than the pressure of the gases existlng in the chamber K, since the gases produced can expand into this chamber as soon as they are formed.

By reason of the upward movement of the contact member C, the are formed between the members C, and D is drawn out, but it is not surrounded by any sheath of gas. In fact there is no compression of the oil in the body N because the gases can expand freely into the chamber K.

An adjustable non-return valve 0 can be provided upon the walls of the chamber K in order to allow of varying at will the maximum pressure of the gases contained in the said chamber, and to ensure the escape into the free air of the gases evolved by the are when they are compressed beyond the said pressure.

A series of battles such be arranged in the chamber K in such a way as to cause the gases to circulate therein so as to increase the cooling eflect.

A regulating valve such as 0 might also be used to allow of the reduction in size or partial suppression of the chamber K; in

such a case it would only benecessary to provide the pipe M with a bottom cover and to connect its flaring or bell-mouthed top to the wall J of the chamber of the latter would then. be reduced to the space R, this being designed to suit the requirements and the said space being placed in communication with the outer air through themedium of the regulating valve.

It willobviously be necessary to provide against the ignition of the gases escaping to the exterior from the valve 0, which however will cause no difiiculty.

In order to prevent any ignition in the interior of the chamber K, and to obviate possible explosion, there may be introduced into this chamber as already mentioned carbon dioxide or any other suitable inert gas, supplied through a pipe such as T, as represented in Figure 2, after the filling with oil.

The apparatus may be completed by a shock resistance; for this purpose there may be arranged in the body N, suitable contacts such as brushes U mounted in an insulating manner upon a support V of any suitable shape and adapted to press upon the tube A; the shock resistance may be formed by coils X connected I between the contact brushes U and the funnel L oriin any other.

manner.

- The switch or cut-out apparatus constructas P and Qcaned in accordance with the invention, may be provided moreover with an arrangement for release at maximum load by direct action, this being located in the metal cap Y sur mounting the body N.

The conductors trolled by the apparatus extend respectively one to the stationary contact members B and D by a' suitable connection, and the other to an insulator Z fixed upon the cap Y of vthe body M. A lead a branching ofi' at-this insulator, enters the said cap Y by an insulating pipe 5, then forms a windin 0 surrounding laminated cores d d, and is ially connected electrically by brushes f with the rod A.

The cores d cl, which are of horseshoe shape, are arranged 111 such a way that their extremities face one another and are separated by an air-gap. The said cores of the electric circuit coil of the current in the winding 0, thereby compressing a device 9 in the shape of an articulated parallelogram. \Vhen the current )fiSSll'l" throu h the windin" reaches a D a D n'edctermined value, the sides of this device 9 are then sufiiciently close together to cause the required movement of a rod h, which through known means produces the tripping of the automatic release mechanism.

The apparatus may also be fitted with a heating resistance j for keeping the onclosed oil at a suitable temperature; in this case the apparatus may comprise a hollow base is forming a reservoir in communication with the pipe M, the said resistance j being arranged in the interior of the reservoir at the position considered preferable in order to obtain a satisfactory circulation of the oil. I

It has been mentioned above that the stationary contact I) is surrounded by a pipe M; it is evident that this pipe M can be suppressed if the expansion chamber K is given a shape such that its bottom end K, (see Figure 3 of the drawings) is at a higher level than the lower edges L of the funnel L, and if its central part is made like a truncated conical basin S, filled with oil, the stationary contact D being secured therein.

What I claim is 1. An oil-break electric switch, comprising stationary and movable contacts, a basin surrounding said stationary contact, a funnel mounted above said basin, the lower opening of said funnel being within said basin, said movable contact guided to pass through said opening into engagement with said stationary contact, an oil-container surrounding said movable contact, said funnel forming the bottom end of said oil-container, and-an expansion chamber in communication with said basin.

2. An oil-break electric switch, comprising a cylindrical oil-containing body, insulating walls to said body a funnel forming. the bottom end of said body, a to cover to said body, a movable contact sli able through said top cover, said contact adapted to pass through the lower opening in said funnel, a basin mounted beneath said funnel, the upper edge of said basin being at a higher level than said opening, a stationary contact arranged within said basin in line with said opening and with said movable contact, and an expansion chamber in communication with said basin.

3. An oil-break electric switch, comprising an oil container, a conical bottom end to said container said bottom end having an opening at its lowest part, a bell-mouths cup beneath said bottom end, the edges of said cup being-at a higher level: than the lower edges of said bottom end, a stationary contact fixed inside said cup, a movable contact within said oil-container, said movable contact adapted to pass throughthe opening in said bottom end into engagement with said stationary contact, and an expansion chamber in communication with said cap.

4. An oil-break electric switch, comprising an oil-container, stationary and movable contacts, said movable contact passing down through said container to engage said stationary contact, a funnel-shaped bottom end to said container, said end having an opening for said movable contact, an oil-containing basin surrounding said stationary contact, said basin having a flaring top extending above the level of the lower edge of said fimnel-shaped end, and an expansion chamber in communication with the top of said basin.

5. An oil-break electric switch,.comprising two oil-containing vessels, the upper of said vessels having a conical bottom end, the

lower of said vessels having an open flaring top, said bottom end extending within said open top, a movable contact adapted to pass down within said upper vessel and through an opening in its bottom end, a stationary contact within said lower vessel in line with said movable contact, and an expansion chamber in communication with the open top of said lower vessel.

6. An oil-break electric switch, comprising an oil-container, a funnel forming the bottom end of said container, a contact movable through the opening in said funnel, a stationary contact beneath said funnel and in line with said movable contact, an oilcontai'ning basin surrounding said stationary contact, the upper edge of said basin extending above the opening in said funnel, and an expansion chamber in communication with the interior of said basin.

7, An oil-break electric switch, comprising an oil-container, a funnel forming the bottom end of said container, a contact movable through the opening in said funnel, a stationary contact beneath said funnel and in line with said movable contact, an oil.- containing basin surrounding said stationary contact, the upper edge of said basin extending above the opening in said funnel, an exansion chamber in communication with the mterior of said basin, and an adjustable escape valve in said expansion chamber, said escape valve opening outwards for the release of the gaseous pressure.

8. An oil-break electric switch, compris---.

ing an oil-container, a funnel forming the bottom end of said container, a contact movable through the opening in said funnel, a stationary contact beneath 'said funnel and in line with said movable contact, an oil-containing basin surrounding said stationary contact, the upper edge of said basin extending above the opening in said funnel, an expansion chamber in communication with the interior of said basin, and battles within said expansion chamber, said baifies exerting a cooling efiect u on the gases.

9. An oil-brea electric switch, comprising an oil-container, a funnel forming the bottom end of said container, a contact movable through the opening in said funnel, a stationary contact beneath said funnel and in line with said movable contact, an oilcontaining basin surrounding said stationary contact, the upper edge of said basin extending above the opening in said funnel, an auxiliary contact supported by said movable contact, a spring controlling said auxiliary contact, a retaining pawl for said auxiliary contact, said movable contact adapted to release said pawl after a given stroke, and an expansion chamber in communication with the interior of said basin.

10. An oil-break electric switch, comprising an oil-container, a funnel forming the bottom end of said container, a contact movable through the opening in said funnel, a stationary contact beneath said funnel and in line with said movable contact, an oil-containing basin surrounding said contact, the upper edge of said basin extending above the opening in said funnel, an expansion chamber in communication with the interior of said basin, and shock resistance coils connected between said funnel and said movable contact.

11. An oil-break electric switch, ing an oil-container, bottom end of said container, a contact movcomprisstationary a funnel forming the able through the opening in said tunnel, a stationary contact beneath said funnel and in line with said movable contact, an oilcontaining basin surrounding said stationary contact, the upper edge of said basin extending above the opening in said funnel, a base piece, an oil-reservoir in said base piece, said reservoir in communication with said basin, an oil-heating resistance in said reservoir, and an expansion chamber in communieation with the interior of said basin.

12. An oil-break electric switch, comprising an oil-container, a funnel forming the bottom end of said container, a contact movable through the opening in said funnel, a stationary contact beneath said funnel and in line with said movable contact, an oil-containing basin surrounding said stationary contact, the upper, edge of said basin extending above the opening in said funnel, a cappiece mounted upon said oil-container, said cap-piece insulated from said funnel, electromagnetic cores pivotally mounted within said cap-piece, means for energizing said cores by the current controlled by the switch, a tri rod for-the automatic release of the switci operating mechanism, an articulated parallelogram arranged within said cappiece, said cores adapted to press upon opposite sides of said parallelogram, said parallelogram adapted to actuate said trip rod, and an expansion chamber in communication with the interior of said basin.

In testimony whereof I hereunto atiix my signature.

PAUL CHARPENTIER. 

